TPS568215: Do you have other parts having OOB feature ?

Hi Hector,

What is the input voltage range of that power source and at what value of threshold you need protection so that we can recommend accordingly. 

Best regards,

Usha.

VOUT regulated by the DC-DC is 4.97V. The other 5V source is 5.04V 

We measured SW node of TPS568215 and confirmed that both high-side MOS and low-side MOS were turned off (OOB function worked)

The other 5V source is close to VOUT (but higher than VOUT).  

For given input and output voltages and protection features we recommend using TPS56A37 buck converter.

Best regards,

Usha.

Hi Usha,

Please explain how TPS56A37 can deal with the condition, thanks.

Hector

Hi Hector,

Input voltage of recommended buck is in the required range and also when output voltage is higher than the threshold it turns off both MOSFETS.

Best regards,

Usha.

Hi Usha,

Is the threshold OVP detect ? When the output voltage becomes higher than 125% of the target voltage, the OVP is triggered.

Do you have parts that have a lower threshold? OOB of TPS568215 is perfect for our application.

Thanks.

Hector

Hi Hector,

You can try adding schottky diode for the recommended buck to prevent reverse current.

Best Regards,

Usha.

Hi Usha,

Schottky diode is the simplest way to prevent reverse leakage but it will increase power loss and heat.

Please recommend DC-DC converters capable of operating safely when the other output voltage exists and exceeds the nominal VOUT but remains below the OVP threshold, ensuring no damage or functional issues occur.

Thanks

Hector

Hi Hector,

Our bucks have reverse current protection and until the limit any reverse current wont damage our buck.

Best regards,

Usha.

Hi Usha,

Do you mean Low-side MOSFET negative current limit in the datasheet of TPS56A37 ?

We used a non-TI buck, which has the same protection feature, but we encountered buck damage when the other output voltage exists and exceeds the nominal VOUT slightly.

The following measurement results were recorded during the abnormal behavior in the BS-LX. Subsequently, the buck converter was damaged, but VOUT remained present due to an alternate output source.

Note that the alternate output source can only affect VOUT when the buck PG is high, meaning the buck will not encounter the alternate output source during ramp-up.  

Thanks 

Hector

Hi Hector,

We will verify the same on the EVM and get back to you. Due to extended shipping timelines, testing will take some time. We appreciate your cooperation

Best regards,

Usha.

Hi Usha,

Thanks for your support.

Can we also expect the verification results to be applicable to the TPS56838?

Thanks.

Hector

Hi Hector,

I support TPS56A37, what are you looking for exactly to see on the TPS56A37 EVM? Just would like to clarify

Please let me know

Thanks,

Calan

Hi Calan,

I’d like to confirm whether the buck converter can operate normally without damage when another output source provides a voltage higher than the nominal 5 V VOUT but still below the OVP threshold.

Three conditions I would like to confirm:

1. Another output source exists when the buck is ramping up

2. Another output source exists when the buck PG is high

3. Another output source exists when the buck is disabled

Thanks 

Hector

Hi Hector,

I will look into this and respond soon.

Thanks,

Calan

Hi Calan,

Appreciate the great support on this.

Best,

Hector